Annatto (Bixin/Norbixin)
What it does
Yellow-orange colour (cheese, snacks).
How it's made
Extracted from the seeds of the achiote tree.
Annatto is a natural yellow-to-orange colour extracted from the seeds of the achiote tree (Bixa orellana), which grows in tropical regions. Its pigments, bixin and norbixin, are used to colour cheese (it gives red Leicester and many cheddars their orange hue), butter, snacks and cereals.
The colour is obtained by treating the reddish outer coating of the seeds. Extracting the seeds with oil yields oil-soluble bixin, while extracting with an alkaline water solution yields water-soluble norbixin; manufacturers choose the method to suit the food being coloured. The seeds themselves are simply the raw pigment source.
The extract is filtered, concentrated and standardised for colour strength, and supplied in oil-soluble, water-soluble or powder forms. As a plant-seed extract, annatto is a popular natural alternative to synthetic yellows and oranges, though it is itself a recognised (if uncommon) allergen for a small number of people.
Possible reactions
Occasional allergic reactions and hives in sensitive people.